My husband purchased Hartz Ultra Guard for 61-150lbs. Was trying to do like most of would do , to get rid of flees. I so wish I had looked on here before this happen. Pepper was 11 years old , would be 12 in December. She was a very outgoing dog, love to fish, swim, walk , run, etc. Her health was good. That day Friday the July 25, 2014, change our entire life. The next day came, she was puking , and not steady on her feet very well. I tried the hot line on the box, no answer on the weekend, try back during business hours. Tried my local vet, they were closed, it was Saturday. Did try there emergency numbers , no answers for help. I decided I needed to think quick. Put her in the bath tub , to get this crap off of her. Thought we were ok, not. Later that night, She was up looking to go outside like she does, but the back legs of my girl went out. My husband had to go get her and bring her in. She finally looked like she could rest at 3:00 in the morning on the 27th of July. Then she starting panting, heavy breathing, and she was done. So sad. Please pass this on, maybe can save someone from this product. It happens so quick, I My miss my Pepper so much. She did not have to die like this. Prayers to all that have had this experience.